The present invention relates to signal generators and processors, and more particularly to digital systems capable of producing complex digital or analog waveforms.
Signals having complex as opposed to simple waveforms are often required for various purposes. Examples of such complex signals are those in the audio range (20 Hz to 20 kHz) encountered in music, machinery noises, and animal sounds and other natural phenomena. Signals having complex waveforms can be produced by utilizing an analog summer to linearly sum the signals produced by several different analog frequency waveform generators. Such generation of complex waveforms requires several inherently narrow range analog filters and their accompanying circuitry, the number thereof increasing with increased complexity of the desired output waveform. However, several analog generators must be used to obtain complex waveforms, and the number of such generators used must increase with increased complexity of the desired output waveform. Also, a different set of analog signal generators must be used if a different type of waveform is desired. In addition linear time delay and phase shifting, especially to a substantial degree, of analog signals is especially difficult if not impossible, particularly since substantial time delay of a signal can affect fidelity of the signal and cause distortion in the frequency components. Furthermore, an analog system requires expensive, high-quality components, and are difficult to design within close tolerances, particularly over the entire audio range.